1. Field of the Invention
The present invention relates to deforming fasteners and, more particularly, to setting a rivet by deforming its head and tail.
2. Prior Art
Various apparatus and methods have been used in the past to connect members together including the use of rivets that pass through the members and have an enlarged or deformed head and tail on opposite sides of the members. Also in the past, solid rivets have been placed in holes of members and two opposing guns or hammers with deforming dies have been placed at opposite sides of the rivet. The guns are usually provided as either an electromagnetic hammer or a hydraulic or pneumatic hammer. When the guns or hammers are activated, they compress the rivet therebetween and deform the head and tail of the rivet to fix the members being fastened to each other.
A problem has arisen with the use of these types of rivet setting apparatus and methods when they are attempted to be used with relatively long shank rivets. Basically, due to the relatively long length of the rivet shank, during the deformation of the rivet a relatively large amount strain energy is absorbed by the material of the rivet that relieves itself and causes the rivet to expand upon being removed from the rivet setting apparatus. Thus, the head and tail of the rivet do not tightly sandwich the members to therebetween. This results in a poor and movable connection.
It is therefore an objective of the present invention to overcome the problems in the prior art as well as provide additional fasteners.